CAN THIS LEAK BE FIXED, HOW HARD CAN IT BE?

[Iron Buddha]

Saw this add on craiglist...i have some question..

"This is a 150 gallon salt water aquarium (glass) and stand.......IT HAS A LEAK IN IT, we think it is leaking in the center seam at the bottom. It would be a good reptile tank or for someone who knows how to fix/repair aquarium leaks. It is a really good tank it has the over flow box built into it along with the plumbing, we just don't have time to deal with a large salt water tank anymore so we didn't try to see if we could repair it. Picture was taken right after we took all the aquatic life out of it so it will be much cleaner in person than this picture. Please email with questions!"

it's only 50 dollars.....so..i was thinking i get some sealant and try my luck..whats the procedure on this ...how common is it that a tank holds after you seal it..? also..i only do fresh water...from the description..do you think this would make a fine fresh water tank too?

 

[skjl47]

Hello; Here is my method of sealing a tank. Another member has posted a video of tank sealing which is very good, perhaps you can find it with a search of this forum.

Hello; here is an old post about sealing a tank with silicone. I have revised it a bit. Resealing a tank can be a chore and may not work the first time, but if you get a good seal it will last for years.
I have found that trying to run a line of silicone only on a portion of a tank often to not work out very well. If a tank leaks, I find it best to reseal all the corners and sides at the same time.
-(In my experience the silicone needs to be applied in all corners while it is still tacky so that it will bond to itself at the apex of each side.)
-(New silicone does not seem to bond to old silicone very well)(Some have posted that it will stick better to the old if the old is well cleaned, I have yet to test this myself.)
I also cut out the existing silicone with a utility knife from all corners before trying to seal with new stuff. I find a shop vac a handy way to remove the bits of silicone. If the first application of new silicone does not seal the leak, I cut out all the silicone that I have just applied and seal the whole thing again. I also find that the silicone tubes that fit in a caulking gun to be the handy way to apply silicone. The tubes of silicone that you squeeze with your fingers are just too hard for me to control and I have not tried to use them in years. You can plug the end of a big tube of silicone with a nail or something round to keep it from curing in the tube too quickly, as you may need it again.
-(Note – When you cut the end of a silicone tube, make the first cut near the end so as to have a small opening. You can always cutoff a little bit more if the bead of silicone is too small.)
Some more pointers. I usually give a tank a good cleaning before applying the new silicone. I use a paste made from ordinary table salt (Without iodine) and a soft sponge.
-(Do not use a sponge or cloth that has been used with soap or chemicals.)
-(I have buckets and sponges that are used only for my tanks.)
The salt paste does not scratch glass and does a fair job at removing the deposits from the surface of the glass (be sure the sponge or cloth used to apply the paste with is not coarse enough to scratch the glass on its own and watch for bits of gravel that seem to jump into the salt paste.) (Letting the salt paste dry to a haze should desiccate most critters if you want to disinfect a diseased tank.)(Note- wetting the glass will soften up the deposits somewhat.) (Also for stubborn mineral deposits, a razor blade in a holder that gives a firm grip is useful. Use a shallow the angle on the blade and keep an eye on the corners of the blade. The corners sometimes get bent and will scratch a thin line. Rinse the salt paste out and let the tank dry well.
Once the tank is clean, I think it needs to be completely dry before applying a bead of new silicone. Dampness tends to hide in the very small seams and in the corners of a tank. I suspect that dampness prevents the silicone from bonding properly to a surface and may result in a leak in a good looking seam. (note- this is not real critical, but try to have the tank in a place where it can sit for a day once the silicone has been applied, so you do not have to move it until the stuff can cure some. Silicone labels often say that it will cure enough in two days to add water. (While I have gotten away with around a two day cure